Should You Add Soil to Miracle Gro Potting Mix?

A potting mix is an excellent option for those looking to start growing some potted plants. Manufacturers precisely formulate this mix to help your garden plants thrive. However, you might wonder if the potting mix requires any amendments such as soil. 

You should not add soil to Miracle Gro Potting Mix since it doesn’t require soil. Miracle Gro formulates its Potting mix to prevent pathogens and other harmful bacteria from contacting your plant through the soil. Potting mixes are ideal for potted plants. 

In the rest of this article, I will discuss some of the most common questions about planting in Miracle-Gro Potting Mix, the difference between potting mix and soil, and a few tips for using potting mix. So, let’s discover how Miracle Gro potting Mix can help your plant flourish. 

Does Miracle Gro Potting Mix Have Soil in It?

First, I would like to go over what you can expect from Miracle Gro Potting Mix and what it contains. Most people know Miracle Gro is full of vital nutrients for your plants, but does it also contain soil?

Miracle Gro Potting Mix does not have soil in it. Instead, it contains peat moss, aged bark, perlite, plant food, and some wetting agent in one effective mix. One benefit of potting mix not containing soil is that it is easier to control harmful contaminants from contacting your plants.

Potting mix not containing soil isn’t necessarily bad as the earth can be a breeding ground for harmful bacteria. However, one could also argue that you are missing out on the helpful microbes and bacteria. When planting indoors, potting soil is valuable as it can help limit how many pests you bring inside your home.

When Should You Add Soil to the Potting Mix?

You should add soil to the potting mix if you plan to use it in a large garden bed. In which case, you can mix it with potting soil. However, some gardeners don’t recommend mixing the two. Ultimately, potting mix is best for you to use in potted plants.

Miracle Gro designs its potting mix to suit potted plant conditions, which generally differ from outdoor plant requirements. You might benefit from a soil addition if you intend to use the potting mix in your outdoor garden.

However, you will be better off buying Miracle Gro Garden soil which suits outdoor planting without additions.

Miracle Grow Potting Mix vs. Miracle Grow Garden Soil

Before I answer any further questions about Miracle Gro Potting Mix, you must understand the difference between the two. Many use the terms potting mix and potting soil interchangeably, but they are not the same. 

Potting Mix

  • It doesn’t contain soil.
  • Potting mix is lighter in color.
  • Potting soil has better drainage. 
  • Potting soil offers limited exposure to harmful pathogens, pests, microbes, and bacteria. 
  • Manufacturers design potting soil specifically for potted plants.
  • This type of soil balances moisture.
  • It contains slow and fast-releasing nutrients for plants.

Manufacturers designed a potting mix for you to use in containers to enhance your potted plant’s growth. This mix provides necessary nutrients for about six months to your plants. So it would help if you planned on refreshing your potting mix after each growing season. 

Garden Soil

  • It contains organic matter, loam, and fertilizer.
  • This soil enhances the texture of other soils. 
  • Garden soil Contains helpful microbes, bacteria, protozoa, fungi, actinomycetes, and nematodes. 
  • You may easily mix it with different soils.
  • It is darker in color.
  • Garden soil contains both slow and fast-releasing nutrients for plants. 

Ultimately, garden soil and potting mix are similar. However, as potting mix suggests in its name, it’s ideal for potted plants, but you can still use it in your garden beds if you wish. In contrast, garden soil is perfect for outdoor gardening beds or greenhouses. 

However, it would be best if you should take care when introducing garden soil into your indoor plant potting mix. Miracle Gro treats their potting soil for pests such as bacteria, mold, and fungi, making it a sterile option for your plants. Garden soil may introduce pests that spread to your other indoor plants, making it rather a risky endeavor. 

When Should You Use Miracle Grow Potting Mix?

So now that you understand the difference between potting mixes and soils, it’s time to talk about when you should use them—specifically when you should use Miracle Gro Potting Mix. 

You should use Miracle Grow Potting Mix in the early spring. This mix works best for potted plants and contains fast and slow-release nutrients. This process means that your plants will have a steady stream of nutrients for up to 6 months. 

That being said, you can always use this mix all year long, especially if you are growing plants in a greenhouse, indoors, or in a warmer climate. Plus, potting mix is readily available throughout the year at most stores. 

Can You Plant Directly in a Potting Mix?

I previously discussed that you don’t have to include extra soil since the potting mix is effective on its own. So does that mean that you can plant directly into potting soil? 

You can plant directly in a potting mix such as Miracle Gro. Potting mixes are designed for potted plants and contain a blend of ingredients to release nutrients to your plants. Potting mixes also tend to be lighter, fluffier, and have better drainage. 

You can always mix Miracle Gro Potting Mix with soil if you wish. However, that isn’t necessary to grow beautiful, healthy potted plants. The potting mix comes entirely ready for you to start planting. 

Tips for Using Miracle Gro Potting Mix

Last but not least, I will go over a few tips you should know when using Miracle Gro Potting Mix. This potting mix is easy to use and will leave your plant looking large and luscious. So let’s explore some things you should know when using this mix.

Miracle Gro Potting Mix tips:

  • Use Miracle Gro for potted plants in the spring. Typically most potted plants enjoy growing during the springtime, making it an ideal time of year for using Miracle Gro for your potted plants. 
  • Pay attention to how old your potting mix is. Potting mix can expire, and the nutrients will no longer be viable for your plants. This issue can happen if an unopened bag sits for too long or comes in contact with moisture. 
  • Refresh your potting mix. Potting mixes typically only last about six months and will need added nutrients to support plant life after this point. You can add compost, more potting mix, or nutrient-rich soils to help with this. 
  • Water well after planting. Watering your potting mix after planting helps unlock the nutrients in the soil for your plants. So be sure to saturate the mix well once your plants are in it. 

So long as you apply these four tips, your experience using Miracle Gro Potting Mix should go great. However, it’s also important to note that the fertilizer used in this potting mix is synthetic, which means it comes from a factory. So if you are looking for a completely organic garden, this might not be the mix. 

However, I recommend Miracle Gro’s Potting Mix on if you want to acquire some. As I previously stated, this mix is great because it can feed your plants for up to six months and may even help you double your plant size.

Frequently Asked Questions 

How Long Does Miracle Gro Potting Mix Stay in Soil?

Miracle Gro Potting Mix stays in the soil for up to 6 months. After six months, your plants will have depleted all of the nutrients from the potting mix, and you will need to refresh the soil. You can restore your potting soil by adding a new potting mix or compost to your pot. 

Do I Need To Amend Miracle Gro Potting Mix for Potted Plants?

You don’t need to amend Miracle Gro Potting Mix for potted plants, as it comes ready for planting. However, over time the nutrients from your potting mix will get used up, and you should add a new potting mix or nutrient-dense soil to refresh it. You can also add fertilizer to accomplish this. 

The real beauty of Miracle Gro is that you need to provide little maintenance besides watering and sunlight for your plants to thrive. You will only need to start fertilizing or caring for your plant after six months, making it an excellent low-maintenance option. 


You don’t need soil for your Miracle Gro Potting Mix. The potting mix comes ready to plant in, and the company explicitly markets this product for potted plants. However, you can mix in some soil if that is your wish. 

After six months, you should add more potting mix to your plants or another nutrient-rich mix such as compost. However, this potting mix comes ready to plant in, and Miracle Gro markets the product specifically for potted plants. 

Alexander Picot

Alexander Picot is the principal creator of, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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